How would I figure out theoretically (or has anyone tried empirically) how many LEDs, specifically WS2812, each channel of the Spark Core could reliably drive?
I guess I could incrementally increase the number of LEDs being driven until I see artifacts but hopefully someone has already tried this or there’s a specification listed somewhere that I haven’t been able to find.
I managed to drive 240 leds using a single I/O pin… 
It’s more of the signal attenuation as the distance increases.
You can always easily add in a buffer to drive it further. :0 but i do remember there’s a limit for the WS218b that i read somewhere…
See this for excitement!
Thanks! I actually found the message torch on your youtube channel yesterday. Glad to see you’re the first to reply here.
Do you think I’d run into problems driving LEDs from 7 I/O pins simultaneously?
I don’t have so many strips and mine came in 4m, 240 leds! Driven using just 1 x I/0 pin 